With the development of mobile communications technologies and the massive deployment of the 3rd generation mobile communications technology (3G for short) networks, high-rate and high-bandwidth services are bringing rich and colorful application experience to people. Especially, recently, a massive growth of smart phones injects new life to communications and also brings more challenges to operation.
In a 3G network, multiple small cells are often deployed in a macro cell, so as to provide better network services to user equipment (UE). When UE moves, a UE handover problem is involved. In the prior art, the 3GPP specifies UE handover procedures in its Release 8/9 protocol. The prior art is described below by using an example in which UE is handed over from a small cell (a serving cell) to another small cell (a target cell): First, the UE sends a measurement report to the serving cell; then, the serving cell sends a handover request to the target cell, so that the target cell performs admission control; then, the target cell sends a handover response to the serving cell; after receiving the handover response, the serving cell sends a handover command to the UE; and the UE performs downlink synchronization and uplink random access (RA for short) processes with respect to the target cell according to the handover command, and finally, the UE sends a handover complete command to the target cell.
However, in a scenario in which small cells are intensively deployed, moving UE may pass through multiple small cells in a short time, and performing a handover procedure according to the prior art will cause an excessively long handover delay and degraded network performance.